Catheter



June 30, 1 959 x AUZ|N 2,892,458

CATHETER ,FiIed July 31, 1956 INVENTOR. Jafirz MAuzin K -MM UnitedStates Patent CATHETER John M. Auzin, Whitman, Mass; Kathleen T. Auzin,executrix of said John M. Auzin, deceased Application July 31, 1956,Serial No. 601,143

8 Claims. (Cl. 128-349) The instant invention relates generally tosurgical rubber accessories and more particularly to a novel andimproved catheter construction.

A primary object of this invention is the provision of a catheter of thedistensible bag type so constructed as to insure that the drainage eyewill never be covered or even partially covered by the distended bagwhen the catheter is in use and under tension.

Another object is the provision of a catheter of the distensible bagtype, which, when the bag is distended to its specified capacity, willnot suffer any decrease in drainage capacity due to stretching of thecatheter shaft within the bag and subsequent diminishing of the drainagelumen diameter.

Another object of the instant invention is the provision of a catheterhaving maximum drainage capacity, the catheter being so constructed asto insure that said capacity will not be impaired or minimized underconditions of actual use.

A further object of my invention is the provision of a distensible bagcatheter so constructed that a portion of the bag remains undistended.

Still another object of the instant invention is the provision of acatheter construction which, although relatively easy and economicallyfeasible to manufacture, is nevertheless more eflicient and dependablein use.

Other objects, features and advantages of the invention will becomeapparent as the description thereof proceeds when considered inconnection with the accompanying illustrative drawings.

In the drawings which illustrate the best mode presently contemplated byme for carrying out my invention:

Fig. l is a side elevation of a conventional, prior art catheter;

Fig. 2 is a fragmentary elevation, on an enlarged scale and partly insection, showing the distal end of a prior art catheter with the bag indistended position;

Fig. 3 shows what may happen to the catheter of Fig. 2 in use when undertension or pull from outside the patients body;

Fig. 4 is a sectional elevation, on an enlarged scale, of a *bag orballoon constructed in accordance with my invention;

Fig. 5 is a fragmentary side elevation, on an enlarged scale, showingthe distal end of a catheter shaft or body prior'to assembly with thedistensible bag of Fig. 4;

Fig. 6 is a fragmentary side elevation, on an enlarged scale, showingthe parts of Figs. 4 and 5 in assembled relation;

Fig. 7 is a side elevation, partly in section and on an enlarged scale,showing the catheter of Fig. 6 in the process of being distended;

Fig. 8 is a side elevation, partly in section and on an enlarged scale,showing the catheter of Fig. 6 distended for use; and

Fig. 9 is a fragmentary side elevation, partly in section 2,892,458Patented June 30, 1.959

ice

and on an enlarged scale, showing the catheter of Fig. 6 under maximumdistention.

One of the prime disadvantages of present-day retention and pressurecatheters of the dstensible' or balloon type, such as are in commonpost-operative use after prostrate gland operations and the like,resides in the fact that once the catheter is introduced into thebladder and tension is applied to the proximal end to position it andplace it under the proper pressure, the whole balloon structure tends toswing or move toward the catheter distal end. As a result of this, theballoon is apt to close the drainage eyes and accordingly impair or atleast somewhat minimize the capacity of the drainage system. Anotherdisadvantage commonly found in pres ent-day catheters of this typeresides in the fact that when the balloon is distended to a specifiedcapacity, the catheter shaft within the balloon frequently stretches,thereby decreasing the diameter of that portion of the drainage lumenand hence decreasing the capacity of the overall drainage system. I Somemanufacturers have attempted to overcome the aforenoted problems bypre-forming the balloons, such as by distending the balloon portionwhile the catheter is still in a wet state and at the same timeintroducing talc or some other like powdered substance to prevent theballoon from sticking while it is drying and curing. This manufacturingtechnique raises new problems, however, in that the distended portion ofthe balloon tends to take a permanent set and to remain larger indiameter at the distended portion. Furthermore, where the balloon ispre-formed in the manner indicated, it will usually be gin to distendfirst at the pre-set portion upon introduction of air or fluid underpressure through the inflating passage, and hence, the desired uniforminflation of'the balloon is not achieved. Thus, it has been founddesirable to provide a catheter of the distensible or balloon type soconstructed as to minimize movement of the distended balloon, when undertension, toward the distal end of the'catheter, at least to the extentof rendering said balloon incapable of covering or blocking the catheterdrainage eyes. Furthermore, my novel and improved catheter constructionminimizes stretching of the catheter shaft within the balloon duringinflation of the latter, thereby insuring that maximum drainage capacitywill be realized at all times.

Referring now to the drawings, and more particularly to Figs. 1 through3, there is shown generally at 10 a conventional catheter comprising anelongated, cylindri: cal shaft or body portion 12 having extending therethrough a drainage lumen 14 and an inflating lumen 16. The proximal endof catheter 10 is provided with the. conventional bifurcated tubes 18and 20 communicating with the lumens 14 and 16, respectively. Adistensible bag or balloon 22 is secured over the catheter shaft 12adjacent to but slightly spaced from the distal end 24 of said catheter.An opening or aperture 26 provided in the catheter wall intermediate theextremities of the balloon 22 communicates with inflatinglumen 16whereby air or fluid under pressure may be introduced into said lumen toinflate the balloon 22. A plurality of drainage eyes 28 are provided atthe catheter distal end, it being understood that said drainage eyescommunicate with drainage lumen 14. The balloon 22 may be secured to thecatheter shaft 12 by any desired means, such as cementing or the like,or it may be integrally formed therewith, such as by the dip method, but.since the method of manufacture forms no part of the instant invention,no further description pertaining thereto I is deemed necessary.

osages Figs. 1, 2 and 3 are directed to a conventional prior artcatheter, and in Fig. 1 it will be noted that the catheter is shown withits balloon partially but not completely distended. In Fig. 2 thecatheter is shown with its balloon distended for use but under notension, and it will h not d h t an ove lapping exists at each end ofthe balloon, as clearly shown at 3,0. It will be understood, of eourse,that the catheter is first introduced into the patients bladder, andthen the balloon 22 is inflated to assome the position shown in Fig. 2.In order to properly position the catheter, and to insure that it isunder the proper pressure, a longitudinal pull or tension in thedirection of the arrow shown in Fig. 3 is applied to the ptOXimalcatheter end, which extends externally of the patient. As will be seenquite clearly in Fig. 3, this tension or pull causes movement of theballoon 22 in a di ection toward the catheter distal end whereupon theballoonbompletely obscures the innermost drainage eye 28 and partiallyobscures the outermost one, thereby greatly minimizing the drainagecapacity. of the system. The catheter drainage is further minimized dueto the fact that during inflation of the balloon 22, the ends thereofstretch or elongate the'portion of catheter shaft lz'that is locatedwithin said balloon, thereby resulting in a diametrical reduction indrainage lumen 14.

' Referring now to Figs. 4 through 9, there is shown a balloonconstruction designed in accordance with the instanfinvention, whichovercomesthe aforenoted diflic ulties' and problems. Thus, I haveprovided a balloon 32 havingathickened wall portion 34exte'nding fromone endi'thereof to a point slightly less than half way of the overallballoon length. The balloon 32 is secured to a catheter shaft'36 havinga drainage lumen 38, an inflating lumen 40, drainage eyes 42, and aninflating aperture 44. As 'will be noted, the construction of thecatheter shaft is conventional in all respects, the. novelconstructional features of the instant invention residing solely in thedetails 'of-theballoon 32. It will be noted that when the balloon 32 issecured in position on. the catheter shaft, such as by cementing or thelike, the thickened balloon por'ti'on34- is preferably located adjacentthe proximal end of the catheter shaft36, whereas the thinner portion35*of'the balloon is located most closely adjacentto the catheter distalend.

"In operation and use, it will be understood that the length of the thinportion 3S is suchthat when all of said portion is distended, theballoon will be of the desired capacity col, cc., or 75 ea). As air orfluid under pressure is introduced through inflating lumen 49 and thencethrough inflatingv aperture 44 to the interior of balloon 32, thethinner portion of said balloon will commence to'distend, while at thesame time, the thicker portion 34 is forced backward toward theproiiimal end of the catheter, all of which is clearly shown inFig. 7.

When thedesi'red inflationof the balloon 32 has been reached, thethickened portion will have reversed and double'dnpp on"itself; as shownin Fig. 8," whereby to pr'ovid'ea relativelyfirin and rigid ancho'ragainst move ment of the balloon toward the catheter distal end, such aswould tend to obscure drainage "eyes 42. l The tendency for balloon 32to resist longitudinal movementtoward the catheter distal end resultsfirst of all from .the natural resistance of the doubled-up, thickenedportion 34 against buckling, which action would necessarily have tooccunif the balloon wereto swing toward the distal end, andsecondlyffromthe fact that the frictionbetween the inner surface of doubled-up,thickened portions 34 and the'cath'eter shaft, as atpoint'46, alsofunctions to resist SuchlongitudinaI movement. It will be understoodthat the specificthickness of the balloon portion. 34 is not critical,but'preferablysaid portion is just thickenough sothat'it will 'not tendto 'diste'nd when air or fluid .under pressure is introducedinto theballoon.

While the catheter is capable of elfective use. when 1-D: flated to thedegree illustrated in Fig. 8,;iLwill: be under:

stood that as further pressurized fluid is forced into the balloon,thickend portion 34 will continue to reverse itself until it has becomecompletely reversed, as illustrated in Fig. 9. In such a position, theballoon is under maximum distention.

Thus, it will be seen that there has been provided in accordance withthe instant invention a catheter construction which at all timesfunctions to insure maximum drainage capacity of the system. Ashereinbefore de scribed, much greater tension can be applied to theoatheter shaft at its proximal end before the balloon will move towardthe distal end than is possible with presentday catheters, and hencethere will be far less tendency for the balloon portion to overlap andcome in contact with the catheter shaft, such as frequently happens inpresent-day catheters and as illustrated in Fig. 2. Furthermore, with myconstruction, there is no tendency to stretch or elongate the catherershaft portion located intermediate the balloon during distention of thelatter such as would cause a reduction in diameter of the drainage lumentherein in view of the fact that undistended portion 34 absorbs thistension when being forced back.

While there is shown and described herein certain specific structureembodying the invention, it will be manifest to those skilled in the artthat various modifications and rearrangements of the parts may be madewithout departing from the spirit and scope, of the underlying inventiveconcept and that the same is not limited to the particularforms hereinshown and described except insofar is indicated by the scope of theappended claims.

I claim:

1. In a catheter having a shaft with a balloon thereon, said balloonhaving an inflatable wall, means rendering one end portion, of saidinflatable wall less readily distensible than the remainder of saidwall, said means being such that the minimum pressure required to fullyinflate said remainder will be insuificient to commence inflation ofsaid one end portion.

2. in the catheter ofclaim 1, said one end' portion. being locatedadjacent thecatheter proximal end;

3. In a catheter having a shaft with a balloon thereon, said balloonhaving an inflatable wall, one end of said wall having an elongatedthickened portion, said portion being of greater thickness than theremainder of said wall, the relation between said thickened portion andsaid remainderjbeing such that the minimum pressure required to fullyinflate said remainder will be insufli cient to commence inflation ofsaid thickened portion.

4, In the catheter of claim 3, said thickenedportion being locatedadjacent the catheter proximal'end;

5. A balloon catheter comprising an elongated. shaft havingsubstantially parallel drainage and inflating .lumenstherein, an eyeatthe distal end of-saidcatheter in communication with said drainagelumen, a distensible bagv on said shaft adjacent tobutspaced fromthecatheter distal end andan'openingin said catheter shaft wallinterconnecting s'aid inflating lumen with said bag. to permit inflationof the latter, saidbag having an inflatable wall, means rendering oneend portionof said inflatable wall less readily distensible than theremaindenofsaid wall, said means being such that the minimum pressurerequired to fully inflate'saidremainder will be insuflicient tocommenceinflation of said one end portion.

6. in the catheter of claim 5, said oneportion being located adjacentthe catheter proximal end.

7: A balloon catheter comprising an elongated shaft having substantiallyparallel drainage and inflating lumens therein," an eye at the distalend ofs'aicl catheter in: communication with said drainage lumen, adistensiblebag on said shaft adjacent to butsspacedfrom.thecathetcrdistal end and an opening in said. catheter shaftall interconnectingsaid inflating lumen withsaid: b g,-.to permit inflation of the latter,said bag having aninflatable walhone.endpert oaot s dw llbe ng of grea ethis ness than the remainder of said wall, the relation between saidthickened portion and said remainder being such that the minimumpressure required to fully inflate said remainder will be insufiicientto commence inflation of said thickened portion.

8. In the catheter of claim 7, said thickened portion being locatedadjacent the catheter proximal end.

References Cited in the file of this patent UNITED STATES PATENTS Auzinet a1 Ian. 19, 1943

